1. Field of the Invention
The present invention relates generally to mobile scaffolding. More specifically, the present invention concerns a mobile scaffolding brake that can be activated from the support platform and when activated generally prevents both rolling and swivelling of the caster wheel. The inventive brake provides a secure restraint of the scaffolding and enables a worker supported on the scaffolding platform to selectively prevent unsafe and inadvertent motion of the scaffolding while the worker is supported thereon.
2. Discussion of Prior Art
It is known in the art to utilize scaffolding to provide an elevated work platform to elevate a worker above a floor or ground surface to complete a task (e.g., painting, drywall finishing, etc.). The scaffolding utilized to provide the elevated work platform is often mobile scaffolding that can be quickly and easily moved from one working position to the next. For example, it is known in the art to support a scaffolding frame with one or more casters that enable the assembled scaffolding to be rolled along the floor or ground surface between working positions. However, it is desirable to prevent the scaffolding from moving when one or more workers are supported thereon.
It is known in the art to provide a scaffolding caster with a brake for selectively preventing the scaffolding from moving. These prior art caster brakes utilize a brake stop that engages the caster wheel and thereby prevents rolling rotation of the wheel. These prior art caster brakes typically include a two-piece housing, with the wheel supported by one of the housing pieces and the brake stop supported by the other. The housing pieces are pivotal relative to one another so that the wheel can be pivoted into contact with the brake stop. One of the housing pieces serves as a foot-activated handle for selectively causing the wheel to be pivoted into engagement with the brake stop. In this manner, the weight of the scaffolding supported by the caster works to maintain the locking engagement between the wheel and the stop.
These prior art caster brakes are problematic and have several undesirable limitations. Several of these problems have been described in Applicants' copending Application for U.S. patent Ser. No. 10/271,634, entitled MOBILE SCAFFOLDING BRAKE, filed Oct. 15, 2002 (hereinafter “the '634 Application”), which is hereby incorporated by reference herein. In addition to the problems identified in the '634 Application, the prior art caster brakes enable the scaffolding an undesirable range of motion when the brakes are activated. For example, when the prior art caster brakes are activated, the caster wheels are still enabled to pivotally rotate—i.e., to “swivel”—relative to the scaffolding frame. Swiveling of the caster wheels is problematic as the caster wheels can re-orient in the direction of an applied force, such as when a third party on the ground inadvertently bumps into the scaffolding, which undesirably allows the scaffold to move in the force direction. This problem is compounded by the common occurrence of only one of the caster wheels having the brake activated, therefore allowing the scaffolding to swing, for example, to pivot around the swiveling, single brake-activated caster wheel. In this regard, the prior art caster brakes are problematic in that each of the four brakes must be separately and manually activated. Such a requirement is undesirable to workers with limited time to complete a job, particularly where the consequences of not activating more than one caster brake could be severe.